Power transmission for motor vehicles



Num Z5', 1924 1,516,578

E. H. PLATT POWER TRANSMISSION FOR MOTOR VEHICLES Filed March 9, 1921 3 Sheets-Sheet l l Q o@ i M I *Il* (n l 2g o ,N l mfg Sm dig MIM D N .I www E@ LQ IVW t ml o\ I o web L @ik @m M@ WITNESS: Q qu Q @da C. S @ZM MM a M Nov. .25, 1924. 1,516,578.

l E. H. PLATT POWER TRANSMISSION FOR MTOR VEHICLES Filed March 9, '1921 5 Sheets-Sheet 2 INVENToR.

l WITNESS: '24m 0S u? M M E. H. PLAT-r POWER TRANSMISSION FOR MOTOR' VEHICLES Filed March 9, 1921 5 Sheets-Sheet 3 v v.rf

WITNESS: NVENTR. 442km @s Patented Nov. 25, 1924.

UNITED STATES,

PATENT UFFICI?"r IEEDWII\`I'H.` PLATT, OF DENVERV'CO'LORADO, ASSIGNOR OF ONE-HALF T0 EDWIN F.

PLA'IT, 0F IORTLAND, OREGON.

POWER TRANSMISSION FOB. MOTOR VEHICLES.

Application tiled March 9, 1921,. `Serial Re. 450,948.

ToraZZ whom t may concern.'

Be it known that I, EDWIN H. Pm'r'r, a citizen of the United States, residinfr at Denver, inthe county of Denver and @tate of Colorado, have invented certain new and useful Improvements in Power `'lransmissions forMotor Vehicles, of which the ,following is a specification. y

This invention relates to self-propelling vehicle and more particularlyk to motor.

driven vehicles of the type commonly known as tractors. f t I A It is an object of my invention to provide in a vehicle of the type referred to, a flexible medium for transmitting the power of the motor to the road `Wheels,which combines eihciency in operation with simpliclty of construction. Another object of the inventionvis to arrange a flexible transmission medlum wlth relation to the road wheels of a motor vehicle so that it can function as a track on soft and slippery surfaces.K4 y .l

A further'objectof the invention 1s to provide a transmission medium without the necessity of the intermediaryof differentialV I direction of the arrow A, Figure 2.

Referrin more specificially to the drawings the re erence character 2 designates the chassis of a motor vehicle suitably constructed for the support ofthe motor and therewith associated parts of the operating mechanism of the same.

The motor which as usual is mounted at the ,frontend of the chassis beneath a protective hood or cover 3, acts upona power shaft ztvwhich -through ythe intermediary of the transmission medium of my invention effects the movement of the road wheels 5 upon which the chassis is supported. 1

The Wheels which in the construction shown in the drawings are placed in tandem pairs at opposite sides of the chassis, are rotata-.blyy mountedr in'boxes 6 on a frame y7 which extends beneath the chassis.

It 1s the main purpose of the under frame to maintain the traction wheels in operative position With `relation to each other and the driving mechanism hereinafter vto be described, and it is in its preferred form composed of two pairs of parallel leaf spring's8 extending at opposite sides of the yroad wheels, short cross bars Y9 which connect the members of each pair, and transverse leaf springs 10 which are attached atthe ends of the pairs of longitudinal springs and are 1(nltrally connected to the chassis of the vec e. e c

Each of the road wheels has a ,drum face 5av between treadsof larger diameter and it which is carried in vthe before-mentioned boxes 6.r

`The treads of the wheels are provided by tires 12 which maybemade of solid rubber, metal or other suitable material or which may be kof the pneumatic. type commonly used on vehicles of lighter construction, and attached to the wheel by means of detachable rims or any other convenient method.

The lexible'medium through which the mechanical power produced by the motor is transmitted to the road Wheels consists of is rotatably supported upon a short shaft y.

two continuous `belts each composed of a plurality of endless wire ropes 13.

The exible multiplex belts are placed around the drum faces of the pairs of roadV wheels at opposite sides of the vehicle and their upper stretches are frictionally engaged by driving wheels 14 mounted atopposite ends ofv a jack shaft which through the medium of a Worm movement is operatively connected with the shaft of the motor.

The peripheral faces ofthedrum portions of the road wheels and the driving wheels are preferably grooved toseparate the endless ropes of the transmission belt and pre'- vent their lateraldisplacement, and flangesH at opposite sides of the'driving Wheels cooperate with the tires of the road wheels to hold the outer ropesj in place.k

.The jack shaft is preferably composed vof three axially alined sections 15 and lconnected for conjunctive rotation by friction clutches 17, the end-sections 15 Acarryingthe driving wheels 14 which engage transmission belts and the kmiddle one 16 supporting the gear wheel 18 of the movement, (the.

worm 19 of which is connected to the motorshaft through the medium of a flexible joint The end sections of the shaft which carry the driving wheels are rotatably supported in boxes 21 on the respective pairs of longitudinal springs of the under frame and the middle section to which the worm wheel. is connected is mounted in bearings in a casing 22 which enclosesthe worm movement and which isl fastened to a convenient part ofthe vehicle chassis.'

The loose members ofthe two clutches are connected to bifurcated arms of levers 23 fulcrumed as at 24 upon a fixed part of the chassis.

The opposite arms of the levers 'have eyes for their pivotal connection with oppositely extending pull rods 25 and 26 which pass loosely through apertures of a crank arm 27 projecting 28 of the vehicle.'`

Nuts 29 and 30 at the ends of the rods are engaged by the arm to transmit its rotary movement to the respective 'levers and y springs 31 and 32 between lthe arms and collars on the rods function to constantly maintain the parts in cooperative relationv to each other. Y y

In the operation of my invention the clutches are normally in the position lto*V eii'ect the rotative continuity of the alined sections of the jack shaft and the -latter which` is rotated by its .connection with a shaft of the motor imparts its movement to the driving wheels 14, whichbear upon the transmission belts under the influence of part of the weightof the vehicle bodyand its load. Y l

The frictional contact of the rotating driving. wheels with'the sagging portions of the belts causes the latter to move longitudinally in the opposite direction and tor thereby im art a rotary motion to thel road wheels whlch support the vehicle through' the medium of the frame on which they are mounted. l 1

The under frame owing to its inherent resilience and that of its connections with the chassis, absorbsL road shocks and increases the frictional contact between the belts and the lwheels with which they engage.

The frame furthermore serves to maintain the road wheels and the driving element of the vehicle in their cooperative relation and in practise the body portion of the vehicle and its load against the disturbing and destructive influences of the lateral stresses to' which ythe road wheels yare subjected on rutted and uneven surfaces. i

The flexible transmission belts also yaid in maintaining the chassis and itsy load in -a state of 'equilibrium and it will be apparentlaterally from the steering shaft that theimpellent action of the drivingV wheels upon the transmission belts and the driving action of the latter upon the road ,wheels increase automatically in ratio to the wheel is idle while that at the outslde of the vehicle continues its impellent. action upony the' respective Vfriction belt and thereby causes the vehicle to move in the given direction.

onto a surface the'rutted or soft'condition of which causes the road wheels to sink bevond the depth of their tires, the enga einent of the lower stretches of the belt with the' ground will cause them toA function as endless tracks, which as in tractors of the track-laying type providesthe traction of adhesion necessary for the movement of the load.

lIt will be understood, however, that this occurs only under the above mentioned conditions and vthat normally when .the vehicle v isl moved over va hard' and uneven surface the engagement of'tlie'wheel treads keeps the belts at a distanceabovethe same.-l

It will` furthermore be seen that myl improved method of transmission greatly increases .thel leverage: by which the power originated in the engine is, caused to actupon the traction wheels," mainly byv reason of the engagement of the flexible.` transmis- In the event of the tractor being Vmoved I' sion mediums with both the` driving and .driven wheels at the peripheriesV thereof.`

Having thus described my. improved transmissionmechanism in a practical and simple form, I'desire it understood that va-` riations in the construction `and arrangement of'the parts'thereof may be resorted to within the'spirit of the invention as defined'in'the following-claims.'

l. In a motor vehicle, the'combinationiof tandem" traction wheels having drum faces of smaller diameterthan their tread circles,`

endless belts carried on vsaid drumiaees, al

vehicle body resiliently supported on said wheels, rotary drive wheels on the vbody frictionally engaging with said beltsy and a motor in driving-connection with the drive wheels.` i

2. AIn a motor vehicle, the combination vof tandem traction wheels having `drum faces of smaller diameter than their tread circles,

on the upper stretches of the endless belts carried on said drum faces, a vehicle body resiliently supported on said wheels, rotary drive wheels on the` body supported on the upper stretches of the belts, frictionally engaging with said belts, and a motor in driving connect-ion with the drive wheels.

3. In motor vehicle, the combination of tandem traction wheels `having drum faces of smaller diameter than their tread circles, end-less belts carried on said drum faces, a vehicle body resiliently supported on said wheels, rotary drive Wheels on the body supported in sags of the upper stretches of the belts, and frictionally engaging with said belts, and a motor in driving connection with the drive Wheels.

4. In a motor vehicle, the combination of a frame, pairs of tandem traction Wheels mounted thereon, said wheels having drum faces of smaller diameter than their tread circles, endless belts carried on saiddru-m faces, a vehicle body resiliently supported on the frame, rotary drivewheels on the body supported on the upper stretches of the belts, and a motor in driving connection with the drive wheels.

5. In a motor vehicle, a. frame` including resilient side members, pairs of tandem traction Wheels mounted on said members, said wheels havin drum faces of smaller diameter than thelr tread circles, avehicle body resilientl supported on' the frame,

rotary drive w eels on the bod supported lts, a'nd a motor in driving connection with the drive wheels. s

6. In a motor vehicle, a frame including resilient side members, pairs of tandem traction Wheels mounted on said members, said wheels having drum faces of smaller diameter thian their tread circles, a vehicle body resiliently supported on the frame, rotary drive Wheels mounted on the body, in connection with the side members of the frame and supported on the upper stretches of the belts, and a motor in driving connection with the drive wheels.

7. In a motor vehicle, tandem traction Wheels having drum faces of smaller diameter than their tread circles, endless belts carried on the drum faces, a vehicle body movable with relation to the traction wheels, rotary drive wheels on said bod supported on the upper stretches of the elts, and la motor in driving connection with the drive wheels.

8. In a motor vehicle, tandem traction wheels having drum faces of .smaller diameter than their tread circles, endless belts carried on the drum faces, a vehicle body movable with relation to the traction wheels, a rotary driving axle on said body, wheels at opposite ends of the axle supported on the upper stretches of the belts, and a motor in driving connection with the axle.

In testimony whereof I have affixed my signature.

EDWIN H. PLATT. 

